A 2-part Transfer transaction results in a double set of Transfer and Transfer Receipt transactions. When a new 2-part transfer is saved, both a Transfer and Transfer Receipt transaction are are created but they are created against the 'Ship Via' Site and not the receiving Site. Prior to posting the transaction, the On Hand balances of the Inventory Lots remain unchanged but the Available balances are reduced from the sending Site and increased in the 'Ship Via' Site (they are unchanged in the receiving Site). After the transaction is posted, the On Hand balances are removed from the sending Site and added to the 'Ship Via' Site and an unposted "Transfer Receipt" transaction remains. This transaction is effectively a new 1-part transfer from the 'Ship Via' Site to the receiving Site. 2-part transfers use a 'Ship Via' Site and are most often used to record:

Transfers that have not yet occurred.
Transfers that take more than a day to complete (i.e., The 3PL Site is a 2 day trip from the 'PRODUCTION' Site).
Transfers that need to account for variances between shipped and received.